VASH2 induced proliferation in human breast cancer cells in vitro and in vivo. (A) In vitro effects of VASH2 on cell proliferation measured by BrdU incorporation, which was measured using ELISA. Absorbance was read at 450 nm (*P<0.05, n=8). (B) Xenograft tumors from mice injected subcutaneously with MCF7-EGFP, MCF7-VASH2, BT474-scramble or BT474-shVASH2 cells. The data are presented as the mean ± standard error of tumor volume of each group. MCF7-EGFP (2.8±1.1 mm3) vs. MCF7-VASH2 (1057.0±402.8 mm3), *P<0.05, n=8; BT474-scramble (94.4±25.5 mm3) vs. BT474-shVASH2 (11.3±3.3 mm3), #P<0.05, n=7. (C) Immunohistochemistry of Ki67 in xenograft tumors. The data presented are the average Ki67 level ± standard error (%) of tumors for each group. MCF7-EGFP (34.8±2.5) vs. MCF7-VASH2 (95.0±1.2), *P<0.05; BT474-scramble (69.8±2.8) vs. BT474-shVASH2 (33.8±1.8), #P<0.05. BrdU, bromodeoxyuridine; OD, optical density; EGFP, enhanced green fluorescent protein; VASH2, vasohibin-2.